A Transported Livengood-Wu Integral Model for Knock Prediction in CFD Simulation
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Engineering - Mechanical and civil engineering, En↗
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IS BLOCKCHAIN A SUITABLE TECHNOLOGY FOR ENSURING THE INTEGRITY OF DATA SHARED BY LIGHTING AND OTHER BUILDING SYSTEMS?
Increasing amounts of data are available from lighting and other building systems. In commercial buildings, these data can be used to improve system and energy performance, detect and diagnose faults, and facilitate maintenance. Building data are not only of interest to owners and operators of the building systems, however. Owners and operators of similar buildings, manufacturers of building systems, utilities, and city agencies also have interesting use cases. Energy data can, for example, be used to verify the performance of energy-conservation measures, issue renewableenergy certificates, and financially settle grid services. Increased data sharing, however, significantly expands the cyber-attack surface, creating new challenges. In this work, blockchain is explored as an option for ensuring the integrity of data that are shared by lighting and other building systems. Blockchain fundamentals and variants are briefly reviewed, and value propositions relevant to building systems are discussed. A recently developed blockchain applicability framework (BAF) that builds upon and addresses the limitations of previous applicability models is also briefly reviewed. The BAF is used to assess the suitability of blockchain over other technologies or approaches for building-data applications, using emerging connected lighting systems as an example use case.
blockchain, connected lighting system, data integr↗
Thermodynamic Consistent Neural Networks for Learning Material Interfacial Mechanics
For multilayer materials in thin substrate systems, interfacial failure is one of the most challenges. The traction-separation relations (TSR) quantitatively describe the mechanical behavior of a material interface undergoing openings, which is critical to understand and predict interfacial failures under complex loadings. However, existing theoretical models have limitations on enough complexity and flexibility to well learn the real-world TSR from experimental observations. A neural network can fit well along with the loading paths but often fails to obey the laws of physics, due to a lack of experimental data and understanding of the hidden physical mechanism. In this paper, we propose a thermodynamic consistent neural network (TCNN) approach to build a data-driven model of the TSR with sparse experimental data. The TCNN leverages recent advances in physics-informed neural networks (PINN) that encode prior physical information into the loss function and efficiently train the neural networks using automatic differentiation. We investigate three thermodynamic consistent principles, i.e., positive energy dissipation, steepest energy dissipation gradient, and energy conservative loading path. All of them are mathematically formulated and embedded into a neural network model with a novel defined loss function. A real-world experiment demonstrates the superior performance of TCNN, and we find that TCNN provides an accurate prediction of the whole TSR surface and significantly reduces the violated prediction against the laws of physics.
Zhang, Jiaxin↗
Consumer Guide to Home Water Efficiency
Learn how a water-efficient home helps you minimize your water use, harness water for reuse, conserve energy, and save money. This fact sheet from Energy Saver includes information on ENERGY STAR-qualified appliances, why to improve water efficiency, and how to save water and energy.
water efficiency, water heating, saving water, wat↗
ADMS Test Bed Updates
This webinar will present results from a joint project with utility partner Xcel Energy in which we evaluated their ADMS application for volt-var optimization using different levels of model quality. We were able to help Xcel Energy understand the trade-offs of telemetry measurements and model quality when managing a feeder's voltage profile to maximize energy conservation. We simulated scenarios with varying levels of model quality and measurement density to evaluate Xcel's options for best using its ADMS. The results help Xcel and other utilities understand how network data affects voltage management as grid operations see continued growth in solar photovoltaic (PV) systems and electric vehicles (EVs).
ADMS↗
Developing a Composite Vacuum Insulated Panel (VIP) Insulation/Vinyl Siding Composite Technology for Retrofitting Residential Walls
This paper reports on a project that has attempted to seize on an opportunity to take a giant leap forward in commercializing a technology that would address a key opportunity to achieve energy savings in the existing residential housing stock. It is typically very difficult to increase the R-value of the walls in existing residential housing as doing so from the inside is disruptive and there have not been good solutions to increase thermal envelope performance from the exterior through adding continuous insulation due to the additional work required to fit existing architectural features to the new wall thickness and to reclad the façade. A high thermal resistivity or R-value per inch product that can be used in these applications offers an excellent solution.This paper summarizes a three-year research project to a produce vacuum insulated panel (VIP)/vinyl siding that would have sufficient R-value to meet the continuous insulation requirements of the 2018 International Energy Conservation Code (IECC, 2018) in all climate zones and has a much thinner profile that will facilitate its application to existing residential homes without the need for expensive retrimming of the architectural details. The paper will supply information on the development of the technology, its thermal modelling, testing, voice of user sessions to solicit input from architects, designers, manufacturers, contractors, and installers, and a techno-economic analysis to gauge its competitiveness with existing product options.
Desjarlais, Andre Omer↗
Developing a Composite Vacuum Insulated Panel (VIP) Insulation/Vinyl Siding Composite Technology for Retrofitting Residential Walls
This paper reports on a project that has attempted to seize on an opportunity to take a giant leap forward in commercializing a technology that would address a key opportunity to achieve energy savings in the existing residential housing stock. It is typically very difficult to increase the R-value of the walls in existing residential housing as doing so from the inside is disruptive and there have not been good solutions to increase thermal envelope performance from the exterior through adding continuous insulation due to the additional work required to fit existing architectural features to the new wall thickness and to reclad the facade. A high thermal resistivity or R-value per inch product that can be used in these applications offers an excellent solution. This paper summarizes a three-year research project to a produce vacuum insulated panel (VIP)/vinyl siding that would have sufficient R-value to meet the continuous insulation requirements of the 2018 International Energy Conservation Code (IECC, 2018) in all climate zones and has a much thinner profile that will facilitate its application to existing residential homes without the need for expensive retrimming of the architectural details. The paper will supply information on the development of the technology, its thermal modelling, testing, voice of user sessions to solicit input from architects, designers, manufacturers, contractors, and installers, and a techno-economic analysis to gauge its competitiveness with existing product options.
Desjarlais, Andre↗
GSA Oklahoma City Federal Building: Smart Buildings Case Study
The purpose of this smart buildings case study is to showcase a leading example of a GEB renovation project in the federal buildings space and provide key information on the project roles, processes, costs, and benefits. The findings from this successful GEB project can be used to help pave the way for additional GEB-ready retrofits in the future. The General Services Administration’s (GSA’s) Oklahoma City (OKC) Federal Building, located in downtown Oklahoma City, Oklahoma, demonstrates that GEB-ready strategies and technologies can be realistically deployed today across buildings with minimal investment. The project team implemented nine energy conservation measures (ECMs) and/or smart building technologies, making it a leading example of a smart, sustainable, and efficient commercial building. The case study highlights the challenges and the lessons learned throughout the project design and execution in addition to some of the best practices and considerations when implementing GEB technologies.
Butrico, Mark↗
Commissioning Guidance for Energy Savings Performance Contracts (ESPCs)
This Commissioning Guidance for Energy Savings Performance Contracts (ESPCs) is DOE’s official guidance for ordering agencies under the current DOE ESPC IDIQ contract. This guidance document explains how commissioning of energy conservation measures (ECMs) and water conservation measures (WCMs) is incorporated into the ESPC process, roles and responsibilities in project commissioning, and key elements of commissioning. This document updates the previous version, released in 2015. This guidance can also be used as applicable in the development of ESPC ENABLE and UESC performance assurance plans.
Walker, Christine↗
Energy and momentum conservation in the Euler–Poincaré formulation of local Vlasov–Maxwell-type systems
The action principle by Low for the classic Vlasov–Maxwell system contains a mix of Eulerian and Lagrangian variables. This renders the Noether analysis of reparametrization symmetries inconvenient, especially since the well-known energy- and momentum-conservation laws for the system are expressed in terms of Eulerian variables only. While an Euler–Poincaré formulation of Vlasov–Maxwell-type systems, effectively starting with Low's action and using constrained variations for the Eulerian description of particle motion, has been known for a while Cendra et al, it is hard to come by a documented derivation of the related energy- and momentum-conservation laws in the spirit of the Euler–Poincaré machinery. To our knowledge only one such derivation exists in the literature so far, dealing with the so-called guiding-center Vlasov–Darwin system Sugama et al. The present exposition discusses a generic class of local Vlasov–Maxwell-type systems, with a conscious choice of adopting the language of differential geometry to exploit the Euler–Poincaré framework to its full extent. After reviewing the transition from a Lagrangian picture to an Eulerian one, we demonstrate how symmetries generated by isometries in space lead to conservation laws for linear- and angular-momentum density and how symmetry by time translation produces a conservation law for energy density. Here, we also discuss what happens if no symmetries exist. Finally, two explicit examples will be given—the classic Vlasov–Maxwell and the drift-kinetic Vlasov–Maxwell—and the results expressed in the language of regular vector calculus for familiarity.
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
Intersection-distribution-based remapping between arbitrary meshes for staggered multi-material arbitrary Lagrangian-Eulerian hydrodynamics
In this paper, we present a new intersection-distribution-based remapping method between arbitrary polygonal meshes for indirect staggered multi-material arbitrary Lagrangian-Eulerian hydrodynamics. All cell-centered material quantities are conservatively remapped using intersections between the Lagrangian (old, source) mesh and the rezoned (new, target) mesh. The new nodal masses are obtained by conservative distribution of all material masses in each new cell to the cell's corners and then collecting those corner masses at new nodes. This distribution is done using a local constrained optimization approach for each cell in the new mesh. In order to remap nodal momentum we first define cell-centered momentum for each cell in the old mesh, conservatively remap this to the new mesh and then conservatively distribute the new zonal momentum to each cell's bounding nodes, again using local constrained optimization. Our method also conserves total energy by applying a new nodal kinetic energy correction that relies on a process similar to that used for remapping nodal mass and momentum. Cell-centered kinetic energy is computed, conservatively remapped and then distributed to nodes. The discrepancy between this conservatively remapped and actual nodal kinetic energy is then conservatively distributed to the internal energies of the materials in the cells surrounding each node. Unlike conventional cell-based corrections of this type, this new nodal kinetic energy correction has not been observed to drive material internal energy negative in any of our testing. Unlike flux based remapping, our new intersection-distribution method can be applied to remapping between source and target meshes that are arbitrarily different, which provides superior flexibility in the rezoning strategy. Our method is accurate, essentially conservative and essentially bounds preserving.
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
BEPAM Model Code and CABBI Simulation Results for "Assessing the Returns to Land and Greenhouse Gas Savings from Producing Energy Crops on Conservation Reserve Program Land"
This dataset contains BEPAM model code and input data to the replicate the results for "Assessing the Returns to Land and Greenhouse Gas Savings from Producing Energy Crops on Conservation Reserve Program Land." The dataset consists of: (1) The replication codes and data for the BEPAM model. The code file is named as output_0213-2020_Complete_daycent-agversion-[rental payment level]%_[biomass price].gms. (BEPAM-CRP model-Sep2020.zip) (2) Simulation results from the BEPAM model (BEPAM_Simulation_Results.csv) * Item (1) is in GAMS format. Item (2) is in text format.
biomass price↗
Generalized energy and potential enstrophy conserving finite difference schemes for the shallow water equations
The conditions under which finite difference schemes for the shallow water equations can conserve both total energy and potential enstrophy are considered. A method of deriving such schemes using operator formalism is developed. Several such schemes are derived for the A-, B- and C-grids. The derived schemes include second-order schemes and pseudo-fourth-order schemes. The simplest B-grid pseudo-fourth-order schemes are presented.
Abramopoulos, Frank↗
Energy and momentum conservation in spin transfer
We utilize simulations of spin-polarized electron scattering by a chain of localized quantum spins to show that energy and linear momentum conservation laws impose strong constraints on the properties of magnetic excitations induced by spin transfer. In turn, orbital and spin dynamics of conduction electrons depends on the dynamical characteristics of the local spins. Furthermore, our results suggest the possibility to achieve precise control of spin-transfer-driven magnetization dynamics by tailoring the spectral characteristics of the magnetic systems and of the driving electrons.
36 MATERIALS SCIENCE↗
An energy and potential enstrophy conserving scheme for the shallow water equations
A three-dimensional finite difference scheme for the solution of the shallow water momentum equations which accounts for the conservation of potential enstrophy in the flow of a homogeneous incompressible shallow atmosphere over steep topography as well as for total energy conservation is presented. The scheme is derived to be consistent with a reasonable scheme for potential vorticity advection in a long-term integration for a general flow with divergent mass flux. Numerical comparisons of the characteristics of the present potential enstrophy-conserving scheme with those of a scheme that conserves potential enstrophy only for purely horizontal nondivergent flow are presented which demonstrate the reduction of computational noise in the wind field with the enstrophy-conserving scheme and its convergence even in relatively coarse grids.
Arakawa, A.↗
Industrial Assessment Center Program (Final Report)
This report summarizes the activities of the Industrial Assessment Center (IAC) at San Francisco State University (SFSU) under the Award No. DE-EE0007705 for the period of October 1, 2016 through September 30, 2021. The work performed under the award and related achievements are summarized per task in the statement of the work in the award.
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
Assessing the Returns to Land and Greenhouse Gas Savings from Producing Energy Crops on Conservation Reserve Program Land
Using land already enrolled in the Conservation Reserve Program (CRP) in the eastern region of the U.S. for producing energy crops for bioenergy while reducing land rental payments offers the potential for lowering the program costs, increasing returns to CRP landowners, and displacing greenhouse gas (GHG) emissions from fossil fuels. We develop an integrated modeling approach to analyze the combination of biomass prices and CRP land rental payment reductions that can incentivize energy crop production on CRP land and its potential to increase soil carbon stocks and displace fossil fuel emissions. Here, we find that conversion of 3.4 million ha in the CRP can be economically viable at a minimum biomass price of 75 Mg –1 with full CRP land rental payment or at 100 Mg –1 with 75% of this land rental payment; this conversion can result in savings of 0.52 and 1.25 billion Mg CO 2 -eq in life-cycle emissions through the displacement of energy-equivalent fossil fuels and coal-based electricity, respectively, and an additional 0.11 billion Mg CO 2 -eq soil carbon sequestration relative to the status quo, with CRP left unharvested over the 2016–2030 period. The soil carbon debt due to the transition from unharvested CRP land to energy crops is short-lived and more than offset by the reduction in fossil fuel emissions. The net discounted benefits from producing energy crops on CRP land through a reduced need for government payments to maintain existing enrollment, higher returns to CRP landowners, and the value of the reduction in GHG emissions could be as high as 16–30 billion by using them for cellulosic biofuels to displace gasoline and 35–68 billion by displacing coal-based electricity over the 2016–2030 period if biomass prices are 75–125 Mg –1 and land rental payments are reduced by 25%.
54 ENVIRONMENTAL SCIENCES↗
Kennedy Space Center’s Energy and Water Conservation Program
America Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Space Coast Section - Our presenter will be Jennifer Hill, PE, LEED AP, Energy Manager for NASA at Kennedy Space Center. Ms. Hill will present on the NASA KSC Energy Program, providing an overview of KSC’s energy program and of projects that have been implemented to reduce energy and water intensity, increase renewable energy usage, and to improve resilience in support of the NASA KSC Mission.
Jennifer Hill↗